The separation of the products of a reaction taking place within a feedstock is currently done in several ways. Examples include batch processing, gravity separation, and centrifugal separation. A new approach is a radial counterflow reactor, which uses a feedstock in a workspace with controlled turbulence patterns created by the rotation of one or more disk impellers, and is described in several disclosures by the present applicants.
There are currently a variety of vessels for the growth or other processing of biological material. The current approaches do not allow for the efficient application of energy throughout the material within the vessel, while simultaneously stripping out exceptionally beneficial or harmful components within the vessel in a continuous process which lends itself to high volume.
Two examples will be used here to illustrate this. The first is the promotion of algae growth for the production of biofuels from CO2. Typically the algae is placed with sterilized water and nutrients in clear vessels such as tubes to allow sunlight to shine in, and CO2 is bubbled up in the tubes to mix with the algae. There is inefficiency in the application of the sunlight energy to the tube, where much of the algae in the interior of the column are shielded from the sun while that on the exterior may get too much. A need exists for improved access of light for photosynthesis to algae in a bioreactor or in a pond.
The distribution of the CO2 in the tube also tends to be uneven because there is not enough mixing. When the algae has had time to create oils and other hydrocarbons, which here will be generally called lipids, then the algae has to be extracted, dried, and processed to remove the lipids. This is a wasteful and energy intensive extra step, and because this is a batch process, there is not a continuous stream that would lend itself to high volume.
It would be preferable to have a continuous lipid production process that did not depend on killing the algae. A goal of research has been to engineer a “lipid trigger” in the algae to make it extrude lipids, instead of storing them internally, and to do so continuously, instead of only producing them intermittently during periods when there is no cell division. But if a live algae colony were able to be continuously producing lipids in this way, there is no efficient way to extract the lipids to keep them from contaminating the algae environment. There is also no way to, at the same time, continuously separate the dead algae from the live ones, to keep the most productive members flourishing. Also, there is a need to strip out the oxygen produced by the algae to favor the forward photosynthesis reaction for enhancing algae growth.
Where algae is in a pond, oxygen is produced by photosynthesis and released to the atmosphere, but dissolved oxygen in the water is consumed by the decay of dead algae, and the depletion of oxygen in the water leads to dead zones where fish cannot live.
In shrimp and fish aquaculture, oxygen is desired, instead of carbon dioxide, but the same need exists for continuous stripping of waste gases and circulation of water to extract feces and other waste material.
To use another example, the combustion of material to create biochar is typically done in furnaces in a batch process. There is a need for continuous mixing that ensures that heat energy will be evenly applied throughout the feedstock, and for an efficient mechanism for continuously stripping out volatile gases or liquids to aid the forward reaction.
The applicants have described a variety of variations on the design of a radial counterflow reactor comprising one or more rotating disk impellers, which has many benefits in establishing a radial counterflow pattern with lighter elements continuously migrating toward the axis, and heavier elements toward the periphery. This radial counterflow reactor idea has been described through its application to the continuous processing of gases, liquids and sludge.